Improvement in steam-engine valves



. ani-fw sam @than @tilting ELTING POST, or BOSTON, MASSACHUSETTS.

Letters Patent No. 94,973, dated September 21, 1869.

AnvrPacman/mira' 1N STEAM-ENGINE vALvns.

The Schedule referred to in these Letters lPatent and making part 0f theSame.

To `all personsV to whom these presents may come:

Be it known that I, ELTING POST, of Boston, ofthe county of Su`olk,andState of Massachusetts, have invented a new. and useful Improvement in-`Steam- Engines; and do hereby declare the same to be fully described inthe followingspecitication, and represented in the accompanying drawing,which denotes a vertical and longitudinal-,section of a steam-enginecylinder and piston,` the steam-chest and valve, and

- the passages thereof, as provided with my invention.

G is the valve-case, which isa' hollow'eylinder, pro'Y videdwithaninduct, a, arranged in the middle of its top.

The valveis shown at D, it being cylindrical, and provided with twochambers, ,b c, which are arrangedwithin4 it, and on opposite sides of achannel, d, that extends' around and within it atjts middle. i

There are two openings or ports leading out of the bottom of. each ofthe chambers b c, they being arranged as shown at e f e f'.

Furthermore, the valve-stem g has two shoulders, h i, arranged on itinmanner as represented, there being extended between them an arm, k,projecting upward from the piston-rod Z.

The passages for leading steam to the opposite ends of the cylinder areexhibited at m and m', `the steamexhaiist passages being also shown at'n and n. Each ofthe sai d exhaust-passages opens at its inner end intoone ofthe chambers b c of the valve, and at its outer end into thevalve-case G.

Furthermore, there are two auxiliary exhaust-passages p p', which arearranged with respect 'to the main exhaustpassages u hf, in manner asshown in the drawing. l

Each of such passages p p may open at one end into a common ednct ordischarge-pipe, and each of such passages should have a port or openingleading upward out of it and into the valve-case; such ports or openingsbeing shownat q q', they being arranged with respect to the passages ee', iu manner as shown. i The novel features of the above-described ismmay be stated as follows:

l First. The auxiliary passages ee', leading out of the mechanchambers bc of the piston.

Third. The opening of' each of the main exhaust passages a n at itsopposite ends into Vthe valve-case.

These features, arranged and employed with others,

as hereinbefore described, will operate in manner as 'may be thusexplained:

We will suppose the valve D to be'at the exact middle of the valve-chestC, that is, so that the pas-- sage d shalll be midway between theconducting-passages m m', leading from the `valve-ease to the two endsof the cylinder A. In this instance, the piston willY be at rest. Next,in order to start the engine, the valve should be moved endwise alittle, or just far enough to cause the passage d tolap a short distanceover one of the mouths of the passages m m. The

steam will next rush through the passage so over-i lapped, which we willsuppose to be the passage fm,\`

and will enter the cylinder and move the piston there-k in. The exhauststeam'will escape from the cylinder through the passage mfand into thechamber e, from whence it will' owintn and' through the passage u', andinto the valve-case and against one end of the valve, and, by itselasticpower, it will instantly move the valve endwise. The valve willcontinue its movement untilv thepassage e may have been 'carried b eyondthe passage g.

During this movement of the valve, the main portion ofthe steam whichmay have been in advance of it in its case will escape through thepassagesru f, the chamber b, and the passages e, q, and p. The steamremaining in the valve-case in advance of thc valve,

not being able to escape, will serve by its'elast-icity as a spring tocushion the valve.

During this movement of the valve, the passaged will have been carriedfully over the mouth of the passage on, so as to supply the cylinderwith the necessary amount of steam to complete the back stroke of thepiston.

During this bach stroke, the arm k of the piston .Will be forced againstone of the tappets or shoulders h z', and will more the valve, so as tolap the passage,

d a little ever the mouth of the passage m. The steam will next rushfrom the said passage d into and through the passage au', thence intothe cylinder, andV will advance the piston. The exhaust steam in thecylinder will at once rush through the passage m into the chamber b,thence through the passages j' and n and into the valveec-ase andagainst the valve, which instantly will be driven by such exhaust steam`in a direction opposite to its former movement, and will continue to somove until the passage e shall have passed by the passage r1' andthevalvc been cushioned by the steam remaining in that part of the casewhich Should we dispense with the passages e e', We could not e'e'ot thecushioning of the valve, but still we' could e'ect its movements bythetexhanst' steam, and

' the escape of the balance of such exhaust steam.

What, therefore, I olaim'as of my invent-ion, is as follows:

I claim the combination and arrangement of the auxiliaryexhaust-passages p p' q q and the main exhaast-passages n fn, with thepassages -m m and with the valve D7 as constructed, with the chambers bc and A the passaves d, j; and f', and passages c e', substantially a'sspecified. v

ELTI NG POST. Witnesses:

l. H. EDDY, J. R. SNOW.

